ORLANDO, Florida -- Recent financial filings show that Florida Gov. Rick Scott has poured another $18 million into his Senate campaign.

The Republican governor is running to unseat Democratic incumbent Bill Nelson for Florida's U.S. Senate seat. 

According to the filings, posted by the Federal Elections Commission, Scott has contributed almost $39 million of his money to his Senate campaign since announcing his run in April. 

The latest donations, totaling more than $18 million, were given between early August and the end of September.  

Combining the personal donations with outside fundraising efforts, Scott's campaign has raised a total of $54,745,372.74.

Although reporting deadlines do not give a clear up-to-date accounting, the latest filings indicate that Scott's campaign has spent much of the cash in the account ($52,734,013.38), leaving a little more than $2 million cash on hand in the campaign account.

Scott, worth an estimated $282 million, poured more than $70 million into his first bid for Florida governor in 2010. He has previously used his personal wealth to his political advantage in fueling his campaigns. 

Nelson has raised $23,486,321.21 to date, according to FEC records. Those are total outside contributions, as Nelson has not loaned or contributed any money to his own campaign.

Financial records show Nelson's campaign has spent $16,643,038, leaving about $8.6 million cash on hand. 

There are about three weeks remaining until the November 6 election, but early voting will begin well before then. 

With contributions totaling almost $80 million, Florida has the second most expensive Senate campaign in the country, trailing only Texas' race between Republican incumbent Ted Cruz and Democrat challenger Rep. Beto O'Rourke. More than $96 million has been poured into that race. 

In contrast, Nelson's re-election bid in 2014 didn't even crack the top 10 list of most expensive Senate races. According to OpenSecrets.org, the 2012 race, in which Nelson won re-election by defeating Republican challenger Connie Mack, raised just more than $24 million among all candidates.